1. Field of the Invention
The present invention relates to carcass alignment systems for holding and positioning a carcass for splitting by an automated saw while the carcass is suspended and continuously moving along a carcass rail.
2. Description of Related Art
One step in the processing of carcasses, particularly hog carcasses, is to split the carcass after it has been eviscerated. Automated saws for accomplishing this task are known, but they often cut inaccurately, which wastes valuable meat and makes subsequent processing more difficult. The difficulty generally lies in accurately positioning carcasses of varying sizes and shapes while the automated saw moves in a known cutting path.
One type of carcass alignment system for holding the carcass during cutting is shown in U.S. Pat. No. 4,653,150 issued to Leining Mar. 31, 1987. The carcass is held between a pair of guide plates that extend out from a frame as the saw is extended out from an opposite side of the frame. The guide plates in this design do not accommodate variations in the size and shape of the carcass. This causes the saw to wander from one side of the backbone to the other. This inaccurate cutting relative to the backbone is highly objectionable to the meat processing industry.
More modern carcass alignment systems use rollers that track the inside and outside of the carcass and continuously reposition the portion of the carcass nearest to the saw as the cutting saw moves. Such designs are seen in U.S. Pat. No. 6,126,536 issued to Kielwasser on Oct. 3, 2000 and in U.S. Pat. No. 5,655,960 issued to Van Horeebeck on Aug. 12, 1997. These designs use pairs of smooth conical or cylindrical rollers, with wider rollers at the back of the carcass than on the inner side. While these designs provide improved accuracy over earlier designs, it has been found that inaccurate cutting still occurs.
A particular problem has been rotating the carcass so that the centerline along the back of the carcass is in the cutting plane. Previously, the back rollers have been either conical or cylindrical and relatively smooth. Such rollers primarily contact the back of the carcass, not the sides and do not conform well to the shape of the back of the carcass. The carcass has been able to slip relative to these rollers and they have not been able to exert a sufficient alignment force to bring the carcass into the desired position. A small misalignment at the back of the carcass, even where the inside is correctly aligned results in a significant cutting error.
Another problem has been aligning the inside of the carcass at the backbone with the saw. Previously pairs of relatively thin rollers with angled roller surfaces have been used to bring the backbone along the inside of the carcass into the desired position. Although this is effective for accurately bringing the backbone to the correct position, it has been found that occasionally the relatively narrow angled surfaces on these narrow rollers will fail to bring the backbone to the correct location
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a carcass alignment system that improves the positioning of both the back and the inner side of the carcass relative to an automated saw as the saw cuts the carcass.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The above and other objects, which will be apparent to those skilled in art, are achieved in the present invention which is directed in a first aspect to a carcass alignment system for positioning a suspended carcass during cutting by an automated saw. The carcass alignment system includes a plurality of back rollers, the back rollers including a back contact section adapted to contact a back of the carcass and a side contact section adapted to contact a side of the carcass; and at least two guide rollers or two guide sleds.
The guide rollers or guide sleds contact opposite sides of a backbone of the carcass and are mounted to move on opposite sides of the carcass from the back rollers to hold the carcass there between as the automated saw cuts the carcass. In the preferred design, both guide rollers and guide sleds are provided and the guide wheels are mounted to the guide sleds. The guide sleds are pivotally mounted to bring the guide wheels into contact with the carcass after the guide sleds have made contact.
Both the guide sleds and the guide wheels are provided with opposed angled surfaces that trap the backbone between them. The guide sleds are preferably wider than the guide rollers and have a linear contact section that greatly increases the contact area with the carcass.
The back rollers are specially shaped to match the expected shape of carcasses to be split. The back contact section is preferably curved. The side contact sections are preferably straight. In the most highly preferred embodiment, there are four back rollers that cooperate to guide the carcass back into the desired position. Two of the four back rollers have curved back contact sections and two have straight back contact sections, while all four back rollers have side contact sections that are substantially straight and extend at a 15 degree angle to the vertical.